20011220101 has 4 divisors (see below), whose sum is σ = 20011969152.
Its totient is φ = 20010471052.
The previous prime is 20011220093. The next prime is 20011220113. The reversal of 20011220101 is 10102211002.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 20011220101 - 23 = 20011220093 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20011220501) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 332911 + ... + 388396.
It is an arithmetic number, because the mean of its divisors is an integer number (5002992288).
Almost surely, 220011220101 is an apocalyptic number.
It is an amenable number.
20011220101 is a deficient number, since it is larger than the sum of its proper divisors (749051).
20011220101 is an equidigital number, since it uses as much as digits as its factorization.
20011220101 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 749050.
The product of its (nonzero) digits is 8, while the sum is 10.
Adding to 20011220101 its reverse (10102211002), we get a palindrome (30113431103).
Subtracting from 20011220101 its reverse (10102211002), we obtain a palindrome (9909009099).
The spelling of 20011220101 in words is "twenty billion, eleven million, two hundred twenty thousand, one hundred one".